Stroke is the leading cause of adult disability in the US and a leading cause of death. Mexican Americans (MA), the largest subgroup of Hispanic Americans, have a substantially higher stroke risk than European Americans, especially at younger ages where the risk is more than double. Given the greater risk and earlier onset, the impact of stroke is disproportionately experienced by MAs. Reasons for increased stroke risk in MAs are poorly understood. More than half of ischemic stroke patients have sleep apnea, a very common and important risk factor for stroke and potentially a risk factor for poor stroke outcome. No published studies have established the prevalence of sleep apnea in MAs to discern sleep apnea's contribution to excess stroke burden in this population. Small studies conducted in academic medical centers have suggested that stroke patients with sleep apnea have particularly poor stroke outcomes, but population-based studies in diverse populations are lacking. The current application seeks to investigate health disparities related to sleep apnea in stroke patients in order to understand the marked ethnic differences in stroke. This research will inform the development of interventions to prevent or treat sleep apnea in MAs, which will reduce the ethnic stroke disparity. The parent study for this project, the Brain Attack Surveillance in Corpus Christi (BASIC) project, is an ongoing population-based stroke surveillance study that identifies stroke cases in Nueces County, Texas. This study has made many important discoveries about stroke in Hispanics. BASIC will continue to identify all strokes in Nueces County until mid year 3 of the current application and will provide detailed 90-day stroke outcome data until mid year 2. The current application will extend BASIC data collection through year 5 month 3 and will add: (1) sleep apnea screening in the acute stroke period that differentiates obstructive from central events, (2) sleep apnea screening for intracerebral hemorrhage cases, (3) access to care measures for sleep apnea, and (4) genetic admixture analysis to investigate how genetics may relate to ethnic disparities in sleep apnea. The application seeks, in a cost-containing fashion, to understand and remedy the influence of a very frequent risk factor, sleep apnea, on a common, devastating disease, stroke, in the largest and fastest growing US minority population.